/Engine/Source/Runtime/Engine/Public/MaterialCompiler.h
virtual int32 StrataVerticalLayeringParameterBlending ( int32 Top, int32 Base, int32 Thickness, const [FString](API\Runtime\Core\Containers\FString) & SharedLocalBasisIndexMacro, int32 TopBSDFNormalCodeChunk, [FStrataOperator](API\Runtime\Engine\Rendering\FStrataOperator) * PromoteToOperator )